basics of tuning delco non $12p

[sprattzvx]

Ken, there is a setting that retards commanded timing by a negative value under certain conditions. eg if you have commanded 30 degrees timing at a given point and the criteria for this parameter have been met then the parameter value of -10 (eg only here) will give you an actual timing of 20degrees spark advance.

Sorry for all the vagueness but it' caught me out before when setting up idle on a cammed L67

good stuff andrew, considering the idle spark advance vs mgc ranges from 26 to 29 btdc, but actual advance is 15 or there abouts, there is something else at play as you said. something to keep in mind when tuning at idle. so how does the ecu determine when its at idle versus in motion, 0 % tps combined with vss 0? looking at a log just now, as soon as the vss gets a value, the tracing bubble suddenly becomes accurate, as soon as vss sees 0, the unseen setting takes over and retards timing.

[krusty]

Ken, there is a setting that retards commanded timing by a negative value under certain conditions. eg if you have commanded 30 degrees timing at a given point and the criteria for this parameter have been met then the parameter value of -10 (eg only here) will give you an actual timing of 20degrees spark advance.

Sorry for all the vagueness but it' caught me out before when setting up idle on a cammed L67

good stuff andrew, considering the idle spark advance vs mgc ranges from 26 to 29 btdc, but actual advance is 15 or there abouts, there is something else at play as you said. something to keep in mind when tuning at idle. so how does the ecu determine when its at idle versus in motion, 0 % tps combined with vss 0? looking at a log just now, as soon as the vss gets a value, the tracing bubble suddenly becomes accurate, as soon as vss sees 0, the unseen setting takes over and retards timing.

Was on the dyno tonight with a VY and checked the value. It's -11degrees park- neutral something or other (using DULW base, DLTK is -15 from memory). I set it to zero so the ips does what it's told. 18 degrees seems to be pretty sweet with stoic idle